# Tagged Questions

Questions on the mathematics behind the famed toy invented by Ernő Rubik.

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### Are all sets of $n$, s.t. $R(m)^n=I$, where $R(m)$ is any sequence of $m$ moves on a Rubik's cube and $I$ is the identity operator, known?

I've written a program that finds the number of times, $n$, one must apply any operation $R_i(m)$, which consists of $m$ single moves/turns/elementary operations on a Rubik's cube, s.t. $R_i(m)^n=I$, ...
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### Will $n$ for $A^n=\mathbb{I}$, where $A$ is any finite operation on a finite group and $\mathbb{I}$ is the identity operator, always be finite?

Will $n$ for $A^n=\mathbb{I}$, where $A$ is any finite operation on a finite group and $\mathbb{I}$ is the identity operator, always be finite? Consider for instance a finite sequence of moves (...
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### requirements for two rubik cubes to be identical

For two Rubik cubes to be identical, what is the minimum requirements? for example are 2 faces and their position sufficient? e.g. 2 side by side face, or two opposing faces of two cubes being same ...
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### About those equivalences in games, is it posible to…

I've heard about some games which can be reduced to TicTacToe, i guess in general there should be some simplier games and other complex games could be reduced to them. I've been wondering, is it ...
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### Using Burnside's Lemma in GAP to handle special variations of the Rubik's Cube?

If you want to count the number of distinct positions of a standard 2x2x2 Rubik's Cube simple counting arguments will suffice: There are 8 corners, all distinct The 8 corners can be in any ...
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### $2 \times2$ Rubik's cube

Let the face of the $2 \times2$ Rubik's cube be defined as the ordered quadruple of colors of it's pieces in a fixed direction (let's say counterclockwise). Does the set of $6$ quadruples define a ...
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### No of unit cubes in a n*n*n cube

Imagine a cubic array made up of an $n\times n\times n$ arrangement of unit cubes: the cubic array is n cubes wide, n cubes high and n cubes deep. A special case is a $3\times3\times3$ Rubik’s cube, ...
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### Is it possible to define a dual for the Rubiks Cube Problem?

The $3 \times 3$ Rubiks cube is already solved algorithmically. What I intended to do was to define Rubiks cube as a Linear Program. I found this link when I was searching for a formulation for it. Is ...
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### Write an element of a group as product of generators

Say we have a finite group $G$ generated by $g_1,\cdots,g_n$. Are there any algorithms or techniques to write any element $g$ as a product of these generators? Ofcourse we could just try all ...
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### Obscuring squares of Rubik's cube

This is a combinatorial question related to Rubik's cube $3\times3\times3$ (and, in the end, its generalizations $n\times n\times n$). I assume that the readers are familiar with this puzzle. Let's ...
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### Running through all permutations of a Rubik's cube

According to Wikipedia a $3 \times3\times3$ Rubik's cube has $43252003274489856000$ permutations. I never tried solving one myself (too tedious), however I wondered, if one could miraculously "solve"...
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### How to create a Rubik's cube type of puzzle that is infeasible to solve? [closed]

Is it possible to create a mechanical puzzle, something like the Rubik's cube, that is infeasible to solve in general, but still demonstrably solvable if one knows the scrambling moves. By "...
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### All equivalent moves on a rubik's cube

Call the primitive moves on the rubik's cube "R,L,U,D,F,B" for right, left, up, down, front, and back respectively. Let us say that I have a permutation of the stickers on the cube written as a word ...
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### Proof that the Rubik’s Cube group is 2-generated

Singmaster (1981) writes, on page 32 of his Notes on Rubik’s Magic Cube: Frank Barnes observes that the group of the cube is generated by two moves: \begin{align*} \alpha &= L^2 B R D^{-1} L^...
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### Random solving of a Rubik cube .

After playing a little with a Rubik cube I thought of the following problem : Suppose we start with a solved Rubik cube (a general one , with $n^3$ cubes) . Then we choose one of the moves , each ...
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### Solving a Rubik's cube in 20 moves or less

Most "cubers" solve a Rubik's cube in about 60 moves, using special algorithms and quick fingers. But any Rubik's cube can be solved in 20 moves or less (cube20.org). Is it possible that there is a ...
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### What are some Group representation of the rubik's cube group?

The Rubik's cube corresponds to valid sequences of moves of the Rubik's cube. What are some group representations of this group (with respect to finite dimensional vector spaces on finite fields)? ...
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### Rubik's Revenge Cube in GAP

I'm trying to create the Rubik's Revenge (4x4x4 cube) group in GAP . Take the following net of the 4x4x4 cube with each sticker labelled with a number. The front, left, upper, right, down, and back ...
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### Can I place the rubiks3cube pieces in the distorted position I intend to get?

Right now I am trying to get the distorted position like this: in each face only one diagonal is solved and no similar colour is on a face other than the diagonal pieces mentioned previously. For ...
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### Rubik's Cube with a missing color

Suppose a color of the Rubik's cube(3x3) is missing, is it possible to find the missing color? Now a brute force method would be solve for all other colors, but that is quite naive.
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### When solving a big Rubik cube (100x100x100), do you reduce the solution to like 50x50x50, and then 25x25x25, and then like 10x10x10 and then 3x3x3?

My question is about Rubiks cube. Say you're solving a 100x100x100 cube (you can see examples in youtube by computer program - https://www.youtube.com/watch?v=0cedyW6JdsQ) When solving a big Rubik ...
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### Probability function for centerpieces of a 4×4 Rubik's cube

I have a question regarding blindsolving of a 4×4 Rubik's cube (a.k.a 4-blind). When a 4-blind solve begins, one is free to pick any rotation of the 4×4 cube. To minize effort needed to solve the cube,...
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### Asymptotic value of permutations of general Rubik Cube

I found this on C|NET, and wondering if there was anything like a $1000\times1000\times1000$ cube? And how many arrangements would it have? Or if this is too much, how about an asymptotic formula for ...
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### Homomorphism from Rubik's Cube group to Symmetric Group.

$R^2$ is the rotation of the right side by 180, $F^2$ is the rotation of the front by 180. Other than this I am completely lost and this blowing my mind. I wish I had more to build off of, but I am ...
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### The mathematics underlying Rubik's games

I am interested in knowing (a little more) about the mathematics underlying some of Erno Rubik's games. I guess we all know his famous cube. I heard at some point that a solution was possible because ...
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### Distance between two positions of the rubik cube .

It's now known that to reach the solved position of the rubik cube from any other position you need at most $20$ moves (a $180^{\circ}$ of a face is counted as one move , not two ) . See for example ...
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### Solving a Rubik's Cube Using Calculus or differentiation? [closed]

I have this question to solve a Rubik's cube using calculus or differentiation and then figuring out whats the shortest time it could be solved in...please help me???
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### What do I need to learn to solve the math behind a Rubiks cube?

I stopped studying math at precalc. What should I study to be able to understand how to solve a Rubics cube using mathematics? I don't think this is an opinion question, and I really want to learn ...
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### How many ways are there to solve a Rubiks cube? [closed]

Friends have been arguing that a rubiks cube could never be mastered cause there are too many different ways to solve it cause there are 43,252,003,274,489,856,000 positions the Cube could have, so ...
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### How many combinations in 10x10x10 Rubik's cube?

I was wondering how many possible combinations there is in the cubes greater than 3x3x3 (4x4x4, 5x5x5, ..., 10x10x10)? We know that in 3x3x3 there are about 4,3 * 10^19 combinations, what about bigger ...
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### Rubik's Cube's Group

Is there an article somewhere with an exhaustive study of the Rubik's Cube Group $G$? Such as computing some subgroups of it or exhibiting some elements of its center $Z(G)$? I tried googling it and ...
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### Rubik's Cube Thistlethwaite Four Phase Algorithm

I am trying to understand The Four-Phase-Algorithm ( Thistlethwaite's 52-move algorithm ) for Rubik's Cube but no easy understandable explaination is given. It would be helpful if given with a small ...
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### how to evaluate combinations of different configurarations of a rubik's cube

how to calculate the total combination number of an rubik's cube ? and what is the number of combination if we fix one face of it with all matched colours , specifically saying blue one ,?? no. of ...
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### $45^\circ$ Rubik's Cube: proving $\arccos ( \frac{\sqrt{2}}{2} - \frac{1}{4} )$ is an irrational angle?

I've been working on a problem related to the 3x3x3 Rubik's Cube where you allow faces to be turned by $45^\circ$ instead of just the usual $90^\circ$. We know for the standard 3x3x3 the cube is ...
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### Can solution to Rubik's cube be seen from the point of view of Markov Decision Process?

Solving Rubik's cube can be thought of as a Planning problem which has : a state space $S$ a set $G \subseteq S$ of goal states (in this case singleton) actions $A(s) \subseteq A$ applicable in ...
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### Imitating smaller Rubik's cubes with bigger ones.

Let's assume we have a 4x4x4 Rubik's cube. With this cube we can imitate a 2x2x2 by considering all 2x2x2 corner cubes as 1 block. Similarly, we can solve it like a 3x3x3 by first solving the 2x2 ...
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### Number of moves necessary to solve Rubik's cube by pure chance

Suppose, random moves are made to solve Rubik's cube. A move consists of a $90$-degree-rotation of some side. The starting position is also random. What is $E(X)$, where $X$ is the number of moves ...
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### How to learn about the Rubik's Cube?

So I just started learning Abstract Algebra and I've recently appreciated an introduction to group theory. Among the interesting avenues of group theory is found in tackling a Rubik's Cube. I've ...
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### Help with proving property of Rubik's cube.

I am looking at these notes, and am trying to prove the following on page 13: Let $C_1$ and $C_2$ be two different unoriented corner cubies, and let $C'_{1}$ and $C'_{2}$ be two different ...
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### Solve All Sequence (Rubik's Cube)

Can you prove/disprove that there is a solve-all sequence of moves to complete the Rubik's Cube from any solvable-position? If so, can you explain how long it is? If not, explain why not. Just to be ...
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### Order of the Rubik's cube group

Associated to the Rubik's cube is a group as described in this Wikipedia article: $G = \langle F, B, U, L, D, R\rangle$. For example, the element $F$ corresponds to rotating the front face clockwise ...
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### Where Does F' in Rubik's Cube Group Singmaster Notation Come From?

Basic 90° : F turns the front clockwise 180° : F^2 turns the front clockwise twice -90° : F' turns the front counter-clockwise Why are we calling the -90° rotation F' and not -F? (source: http://en....
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### Rubik's cube computing algorithm

Is it possible to solve a 3x3 Rubik's cube using a tree similar to a 'mini-max game tree' (listing all possible unique moves, then listing further moves from this and so on), or is the sample space ...
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### Minimum number of stickers required for 3x3 Rubik's Cube

Lately, the stickers on my V-Cube have been peeling off, and I became curious: what is the minimum number of stickers I would actually need in order to represent each unique configuration? I have but ...
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### Miniature Rubik's Cube

$R$ is a clock-wise twist of a right-hand face and $U$ is a clock-wise twist of the upper face of a $2 \times 2 \times 2$ Rubik's Cube. Find the order of the subgroup generated by $\{R, U\}$
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### How to use group theory to solve larrys square iphone app

There's a 2 d version of rubiks cube on apple app store. How can group theory give an algorithm to solve the iPhone app:larry's square.